Heat exchanger and ash collector



Oct. 6, 1953 5, ox 2,654,582

HEAT EXCHANGER AND ASH COLLECTOR APPARATUS Filed July 28, 1949 3 Sheets-Sheet l INVENTOR HAROLD 0. FOX 5 a v BY FM- M ATTORNEYS Oct. 6, 1953 H, ox

HEAT EXCHANGER AND ASH COLLECTOR APPARATUS Filed July 28, 1949 3 Sheets-Sheet 2 HAROLD 0. FOX 7'0 ATTORNEYS Oct. 6, 1953 ox HEAT EXCHANGER AND ASH COLLECTOR APPARATUS Filed July 28, 1949 3 Sheets-Sheet 3 l A iiiiiiiiih i-ihiii-nliiniuiiiiiiii-t I'l lli;

INVENT OR HAROLD D. FOX

ATTORNEYS Patented Oct. 6, 1953 UNITED STATES ATENT OFFICE HEAT EXCHANGER AND ASH COLLECTOR APPARATUS Harold D. Fox, Pontiac, Mich.

Application July 28, 1949, Serial No. 107,190

4 Claims. (01. 257-172) This invention relates generally to heat conserving devices and has particular relation to a fuel economizer which is especially adapted for ready attachment intermediate the exhaust pipe of a coal, oil or gas furnace, boiler or the like and the chimney flue.

One object of the invention is to provide a. fuel economizer which will be capable of selectively or simultaneously elongating, deflecting, varying, controlling, dampening, conveying and equalizing the exhaust gas flow as it is received directly from the furnace.

Another object of the invention is to provide a fuel economizer which will be capable of extracting and collecting a maximum amount of soot, cinders and other solid combustion products entrained in the exhaust gas flow.

Still another object of the invention is to provide a fuel economizer which will be capable of preventing or minimizing an explosion of the exhaust gas flow therein, or in the furnace itself, by accommodating the initial expansion of the exploding gases and thereafter by-passing the expanded gases directly into the chimney flue.

A further object of the invention is to provide a fuel economizer which will be capable of extracting the maximum amount of heat from the exhaust gas flow and radiate or transfer such heat to the surrounding space without interfering with the normal operation of the furnace.

Another object of the invention is to provide a fuel economizer which will be capable of being adjusted so that it will operate under self-regulation to achieve the foregoing objects.

Another object of the invention is to provide a fuel economizer which will be capable of operating under a very high degree of efiiciency and will result in a substantial saving of fuel.

Another object of the invention is to provide a fuel economizer which is simple and inexpensive in construction and is adapted to be securely and easily positioned in a substantially rectangular volume of relatively small width usually available intermediate the furnace and the chimney.

These and other objects of the invention will be readily apparent and understood by reference to the following specification and accompanying w s wherein:

Fig. l is a perspective view of a fuel economizer in accordance with the present invention where in the sides and top are constructed from a single sheet;

Fig. 2 is a perspective view of a fuel economizer in accordance with the present invention showing the outer shape in elongated cubical form;

Fig. 3 is a cross-sectional view taken on the line 33 of Fig. 2;

Fig. 4 is a cross-sectional view taken on the line 44 of Fig. 3;

Fig. 5 is a cross-sectional view on the line 55 of Fig. 3, showing the construction of the ash pit assembly:

Fig. 6 is an enlarged outside view of the balfle plate handle and regulating assembly;

Fig. '7 is an enlarged inside view of the baflie plate regulating construction showing the baffle in dumping position in dotted lines;

Fig. 8 is a sectional view showing the detail construction of one of the baffle regulator assemblies;

Fig. 9 is an enlarged view taken partly in section showing the detail construction of the intake port of the fuel economizer for connection to the exhaust port of the furnace; and

Fig. 10 is an enlarged sectional view showing the detail construction and arrangement of the baffle plates wherein alternate ends of the baflles are cut away to permit a serpentine tortuous flow of the hot exhaust gases in a vertical direction.

Referring now to Fig. 1, there is illustrated a fuel economizer embodying the present invention wherein the side walls and top are formed of a single sheet Ill, as of sheet metal. The front end plate II and the back end plate l2 and bottom plate H, see Figs. 3 and 4, as assembled, as by welding, to provide airtight seams and connections. Preferably, angle irons M are joined along the top ends of the unit, as by welding to pro- Vide rigidity and strength. Similarly, angle irons l5 are joined along the bottom sides of the unit,

as by welding for rigidity and additionally as slide plates for the ash collector Ml. Preferably, angle irons or bars K5 are mounted vertically and generally centrally on the inner side of the side walls It for rigidity to prevent collapse or ballooning thereof. Additionally, brace struts [1 are secured thereto for the aforesaid purpose.

A partition [ii is mounted, as by welding, parallel and adjacent to the back end i2 and at such a distance therefrom to provide a vertical flow path chamber A. The partition I8 terminates short of the top and bottom to provide a space for the relief pressure valve element 2% and ash collector 40 respectively.

The relief pressure valve element 20 generally comprises a valve or flap 2| suspended from a hinge 22 which is secured to a frame 23 mounted on the top of the unit between the back side I2 and the partition l8 and between the top of the unit and the top of the partition IS, the angle of inclination being so adjusted with the weight 24 that an excess pressure or explosion in either the furnace or fuel economizer, or both, will cause the relief valve l8 to swing open and permit the excess gas to be vented directly through the valve element 20, into the chamber F and out the exhaust port 80.

A series of parallel bafile plates 30 are swingably mounted between the partition l8 and the front end II, by means of rods 35 so that the bafiles are rotatable about the longitudinal axis of the rods 3|. Preferably, bearing discs 32 are provided to house the supported ends of the rods 31. The baflles 30 are mounted off center of the rods 3| with their major area on one side of the rod and are provided with suitable weights 33 on the other side of the rods 3i to maintain the baflles in substantially horizontal balance.

As shown, the series of baffles are mounted so as to provide flow path chambers C, D, E and F. As shown in Figs. 2, 6 and 8, the rods are provided with handles 34 which extend outside the front of the unit. Preferably, heat insulating handles 39 are provided as a suitable hand grip.

The rods 31 extend through the front of the unit. An adjusting track 35 is mounted on the front of the unit on an angle of about 35-45 clockwise of horizontal and intersecting the path described by the handle 34. A bolt and wing nut assembly 35 is slidably fixed to the track 35 above the handle 34 to limit the upward movement of the handle 34 as caused by overbalance from the weight 33. The bolts 37 are preferably provided with a metallic sleeve 31' surrounded by a non-metallic sleeve 38', as of rubber, to reduce noise caused by contact of the arm 34 in its swinging movement. Likewise, as shown in Fig. 6, a second bolt and wing nut assembly 31 may be slidably fixed on the track 35 below the handle 34 to limit downward movement of the handle 34, as shown in dotted lines, caused by accumulation of a load of ash, cinders, etc., on the bafile plates which results in dumping of the baffle as shown in Fig. '7. It will also be apparent that the baflle position regulating means comprising the weight 33, handle 34, track and bolt and wing nut assembly 36, 31 not only permit individual adjustment of the bafiies 34 in the normal horizontal position and limit their dumping movement but also permit variable adjustment of the flow path of the exhaust gases by varying the shape of chambers C, D, E and F.

An ash collector 4D is slidably mounted in the bottom of the unit on the base legs of the angle iron supports 15 as shown in Figs. 3, 4 and 5. The ash collector 49 generally comprises an opentopp'ed rectangular box having C-shaped end portions '4! forming a handle grip flange 42 for withdrawing the collector from the unit and a deflector plate '43 serving to deflect the downward flow path 'of the exhaust gases and ashes from the chamber A. A brace rod and carrying handle 44 is centrally mounted between the sides 45 for maintaining rigidity and for providing carrying means for transporting and emptying the collector. Two pairs of oppositely positioned guides 46 in the form of bevel-edgedstrips are mounted on the inner side walls of the unit for properly positioning the ash collector along the base slides [5.

A door 5!! on a suitable continuous hinge 5i and held in closed position by latch'and hook 52 is provided on the bottom front end H of the unit for access to the ash collector 46. Pref The fuel economizer of the present invention is provided at its base with extension legs 50 comprising an extension link 6| adjustably mounted along a longitudinal slot 62 between the angle iron base leg 63 and the bottom frame plate 64, as by means of nuts and bolts 65, 66. This adjustable base leg arrangement permits variations in the height of the intake "and exhaust ports 10, and permits level alignment of the unit on rough flooring.

The intake port 10 is preferably mounted on a side H], see 'Fig. 1, or on the back plate I2 as shown in Fig. 3 and generally comprises a sleeve intake pipe ll provided with an outer annular extending flange 12 for securing the port 10 to the wall l2, as by means of bolts 13 to provide a substantially airtight connection.

The exhaust port 80, as shown, is similarly constructed and comprises a sleeve intake pipe, a-zflange and securing bolts.

In a preferred form as shown in Fig. 9, the ports 15 are provided with annular extending flanges '16 adapted to fit snugly against the inside of the wall of the unit. An L-shaped flange ring H is adapted to fit snugly against the outer contacting joint formed by the wall and the port and is secured thereto by means of bolts 78. The outer end of the port 15 is provided with alternate slots 19 and fingers 81 for providing a snug fit with the exhaust furnace pipe or chim ney flue pipe 82. Preferably a clutch band or ring clamp 83 with securing bolts 84 is provided to further seal the connecting joint.

Referring now to Fig. 10, the construction shown is similar to that of Fig. 3 with the exception that the baffles are provided with alternately staggered openings 38 which cause a serpentine flow path of the'exhaust gases.

In operation 'of the fuel economizer of the present invention as shown in Figs. 3 .and 4, the exhaust gas from the furnace enters the unit through the intake port 10 and is forced downwardly through chamber A. into chamber '3, and under the partition l8 upwardly into chamber C. In its ascent from chamber C to D, D to E and E to F successively, the gas is forced through the spaces between the baffies 30 and side walls, as shown in Fig. 4. This construction not only retards the gas flow but also forcibly directs the hot gases against the sides of the unit. Likewise, the ascending gases are forced through the spaces between the front end I l of the unit and the ad jacent end of the baflies.

By this means, an important feature of the invention is accomplished; namely, the hot gases are forcibly directed against and contact all four side walls of the unit, thereby extracting a maximum amount of .heat from the gases. Additionally, another important feature of the invention is accomplished; namely, the velocity of the hot gases is retarded sufficiently to permit extraction of the maximum amount of heat without appreciablydisturbing the furnace draft. Additionally, a partial vacuum effect is created in the unit by virtue of the internal construction and the airtight wall construction. In addition, the flow of hot exhaust gases is directed downwardly in chamber A from the intake port "It and horizontally along chamber Bwhich is a major heat exchange area because of its close relation to a normally cold floor. .Also, the partition 18 is heated by the incoming hot gases in chamber A and transmits its heat to the relatively c001 gases in chambers C, D and E. This heat exchange efiect is particularly achieved 1 by the opening 38 as shown in Fig. 10. It will thus be apparent that the heat in the incoming gases is distributed throughout the entire unit to provide a maximum transfer to thearea surrounding the casing.

In the event of an explosion in the furnace or in the unit itself, the pressure in the chamber A will force open the relief pressure valve 20 and permit direct flow of the gas from chamber A to chamber F and out the exhaust port 80.

In the form illustrated in Fig. 10, the ascending gases may follow the same path as shown in Fig. 4 along the sides of the unit and follow the serpentine tortuous path as shown in Fig. 10. I By this means, the gases are particularly directed horizontally along the chamber C toward and vertically through the opening 38 in the bottom baffie 30, thence in a reverse h rizontal direction along the chamber D, then vertically through opening 38 in the central bafile 3 thence horizontally in the chamber E, upwardly through opening 38 in the top bafile, horizontally along chamber F and thence out the exhaust port 8!].

By this means, the hot gases forcibly contact the two sides of the unitin the four longitudinal areas defining the chambers C, D, E and F as well as forcibly contacting the front end of the unit at the two openings 38 and also the top of the unit serving to define the top of the chamber F. Thus, the maximum area of the Walls of the unit are forcibly contacted by the hot exhaust gases thereby resulting in maximum extraction of heat therefrom.

In operation, the surfaces on the baflies 3!) gradually accumulate ash, soot, etc., the weights 3% being adjusted to permit dumping whenever the desired load of ash is accumulated on the baffles,

the ash collector 40 being positioned under the baffles 3!] to receive the dumped ashes.

The dampening force may be modified readily by adjusting the angles of the bafiles in their normal position as controlled by the position of the bolts 3'! on the tracks 34 limiting the upward or downward movement of the baffle lever arms 34. Thus, the flow path of the ascending gases may be modified by lowering the normal position of the bafiles 30 so that a majority of the gas will be forcibly directed against one of the side walls.

It will be understood that the construction of the fuel economizer of the present invention may be modified by those skilled in the art without departing from the spirit and scope thereof as defined by the appended claims. For example, the position of the intake port 70 may be varied so long as it communicates with chamber A, B or C. Likewise, the position of the exhaust port 85 may be varied so long as it communicates with chamber F. Although the construction disclosed is particularly adapted for welded connections, it will be understood that rivets, bolts, etc., may be used as the connecting means so long as a substantially airtight and rigid construction is achieved.

While the invention is not limited to any specific dimensions, it has been found by actual practice that with eight inch intake and exhaust ports, the openings 38 in the bafiies 313 (see Fig. preferably are in the form of a '7 x 9 inch rectangle having an area of about 63 square inches with the baffles having about three times this area. Also, with an eight inch intake port, the side walls preferably comprise about a 48 inch square, the end walls being about 9 inches wide, thereby giving a relative ratio of about 400 cubic inches to the unit for each square inch of intake port area. Additionally, it has been found that for such a proposed construction, a space of about three-fourths of an inch between the battles 30 and the side walls is preferable for the most economical operation.

While the invention has been described in a preferred embodiment, it will be understood that further variations may be made by those skilled in the art and it is intended that such modifications be included as coming within the scope and spirit of the appended claims.

I claim:

. 1. A heat conserving and ash-collecting device for attachment between the exhaust port of a furnace and a chimney flue comprising a substantially airtight, vertically extending casing, a vertical partition in said casing extending short of the bottom of said casing to provide a downwardly extending vertical passage and an upwardly extending vertical passage, said passages communicating at their lower ends, an inlet port in said downwardly extending passage and an exhaust port in said upwardly extending passage, a plurality of horizontally extending baiiles positioned at various levels in the upwardly extending passage and having their peripheries spaced from the walls of the passage for directing hot gases against the walls and for collecting ashes thereon, manually settable means for positioning and holding said bafiles at desired angles to the horizontal for varying the peripheral spacing of the baiiies from the walls of the casing and automatically operable means for dumping the ashes from the bafiles comprising, means for pivoting the baffles off center so that a major area of the baffles is on one side of the pivot axis and a minor area is on the other side and means for normally maintaining the major area of the baffles and the minor area of the bailies in balanced relation, whereby after a substantial amount of ashes have collected on the baffles they will become unbalanced in favor of the portion having the major area, thus causing them to pivot downwardly discharging the ashes.

2. A heat conserving and ash-collecting device as set forth in claim 1, wherein said baffles are fixed to horizontally disposed rods pivotally mounted on one end in the casing, and wherein said manually settable means comprises, a plurality of handles fixed to said rods and extending outside the casing, a trackway positioned adjacent each handle, and a pair of manually settable stops variably positionable along each trackway on either side of the handle for limiting the movement thereof and wherein the minor area of the baffies is weighted to make it slightly heavier than the major areas of the bafiles, thereby normally urging the handles against their respective stops.

3. A heat conserving and ash-collecting device as set forth in claim 1, wherein said vertically extending casing is elongated, narrow and rectangular, and wherein said vertical partition is positioned substantially parallel and adjacent to one end of the casing so that said upwardly extending vertical passage is of substantially larger cross-section than said downwardly extending vertical passage.

l. A heat conserving and ash-collecting device as set forth in claim 1, wherein the bafiles are mounted in vertical stacked relation in said upwardly extending vertical passage and have their ends spaced alternately from the walls of said fis ssm g 01m in m fi e Qt his patent UNITED STATES Number Name Date Fellett July 16, 1878 Andersen July 27, 1886 61s on et a1, July 30 1895 Mainz et a1. Mar. 14, 1899 Vogel Aug. 26, 1902 Anthony Dec. 9, 1913 Hansen Aug. 23, 1927 Number 015.91; et a1 53.3", Apr. 21 1936 P fozold et al. Maw Aug 4.; 1936 Bollhaimer M Jan, 12, 1 37 Hqffman 1". Feb. 9, 1937 Tigner H awn-w Sept! 3. 19 0 FQREIGK PATENT-5 try Date ermany HMS! July 2L, 1922 Germany um-1, Sept! 13, 192.2 F ance mud-um eb- .8, 1926 

